Dogbone??
 

There is what appears to be a dogbone shaped weight on the rear end at the driveshaft. Is this actually a weight? If so, is it necessary? What effects will it have, if any, on performance and driveability if I remove it? Thanks for the help.
Caymon

it is a balancer weight for the rear end it is setup for the stock gears so if you change the ring and pinion it's worthless unbolt it hold it in your hand step outside and drop it into the trash can.

I believe you are referring to the anti vibration counterweight.

I left mine on after the gear change because it is a nice place put the jack when raising the rearend (I don't like to put the jack at the seal on the rear diff).